Formal Aminocyanation of α,β-Unsaturated Cyclic Enones for the Efficient Synthesis of α-Amino Ketones
作者:Chunrui Sun、Matthew J. O'Connor、Daesung Lee、Donald J. Wink、Robert D. Milligan
DOI:10.1002/anie.201309435
日期:2014.3.17
occurs through the formation of pyrazolines by means of a formal dipolar cycloaddition of cyclic α,β‐unsaturated ketones with lithium trimethylsilyldiazomethane followed by novel protonolytic NN bond cleavage under mild conditions. This two‐step process provides a diverse array of structurally complex free and mono‐alkylated α‐amino ketones in excellent yields.
Preparation of Tethered Aldehyde Ynoates and Ynones by Ring Fragmentation of Cyclic γ-Oxy-β-hydroxy-α-diazo Carbonyls
作者:Ali Bayir、Cristian Draghici、Matthias Brewer
DOI:10.1021/jo902405f
日期:2010.1.15
Cyclic gamma-oxy-beta-hydroxy-alpha-diazo carbonyls undergo Lewis acid induced ring fragmentation to provide either ynoates or ynones tethered to an aldehyde, ketone, or ester. The fragmentation precursors are convenient to prepare by adding lithiated alpha-diazo carbonyls to alpha-oxy ketones. The fragmentation appears general and provides a variety of functional group-rich products in good to excellent yield.